I haven’t seen many folks attributing the inability to get parts to “continuous innovation.” Most Tesla’s are Model 3 or Model Y, which have been around for a while now. Tesla’s been making/ordering the parts for those cars for years and years, without a whole lot of changes or refreshes (not too many Highlands on the road yet).
I suspect it’s more that Tesla has other priorities than making sure that there’s an adequate stock of extra parts available to service their fleet timely. They’ve been trying to grow like gangbusters, and so it may simply be that their focus is on growing their production and deliveries. Ensuring an adequate supply of spare parts is an unglamorous part of what a mature auto company has competencies in - that may not be the area where Tesla wants to differentiate itself. And running on a dealerless model, when dealers are an important provider of service infrastructure, may not help either.
Not sure if it will come up tomorrow, or whether it would change if it did. Remember, Tesla isn’t even a car company anymore. It’s an AI/robotics company that appears to many to be a car company. Maintaining optimal levels of replacement door panels for body repairs is the kind of stuff that a boring old car company worries about, not an AI/robotics company.